Introduction

Vancouver Trees Study

Author - Blair Cheredaryk. Published on October 24th, 2023

We will be taking a look at the type of tree species in the city of Vancouver, Canada. The dataset is taken from Vancouver Street Trees dataset, accessed through this link. I want to take a look at the species and how they relate to the different neighbourhoods. A few questions I would like to answer are

  1. What are the 4 most populated tree species?
  2. Which neighbourhood has the most and the least of each of these species?
  3. Does it matter what side of the street the tree lives on for height?
  4. Which neighbourhood has the tallest and shortest tree and what side of the street is it on?
  5. Which neighbourhood has the most over amount of trees and which has the least?
I'm really curious which type of species lives in which neighbourhood and which of those species is the tallest.

The data were obtained from The city of Vancouver's Open Data Portal and follows an Open Government License

Lets read in the dataframe from the website given.

Let's describe the data to see what we find.

We will be using the species_name, street_side_name, height_range_id, and neighbourhood_name cols in this presentation. These give us great data to work with as there are no missing values in each col.

A few takeaways from the describe function:

1. There are 5000 trees
2. The diamter ranges from 0 (must be an ommitted value) to 71.
3. The min tree height is 0 (must be ommitted which throws off the data)
4. The max tree height is 9
5. The average diamter of all the trees is 12.34

Rubrum - Killarney and Riley Park have the tallest at 6 metres and its on the odd side of the streetA few questions I would like to answer are

1. What are the 4 most populated tree species?
2. Which neighbourhood has the most and the least of each of these species?
3. Does it matter what side of the street the tree lives on for height?
4. Which neighbourhood has the tallest and shortest tree and what side of the street is it on?
5. Which neighbourhood has the most over amount of trees and which has the least?

From this chart we can see that Renfrew_Collingwood has the most trees and that Strathcona has the least.

Now lets see which are the most common tree species in Vancouver. I will filter the data so that we only use the species which have over 50 occurences.

Lets chart this!

From figure 2 we see that Surrulata, Platanoides, Cerasifera, and Rubrum are the four most populated trees species in Vancouver. Now lets find out which neighbourhoods have the top 4 species of trees. I'll filter out the top 4 species into a new df first.

Its hard to tell any data from figure 3, Its hard to see to compare the species to the neighbourhood with all the data stacked . Lets facet this into each species to get a clear look at the data

This is better but its still a bit hard to read as there are many neighbourhoods. We will add a few selection tools but first lets break this chart down into the sides of the street the trees live on to see if it clears up the data.

This looks great so lets add a title and subtitle then add some functionality!

I like the color choices and how the legend tells us that but I think we can get more info on the number of trees of the top four species, there neighnbourhoods, and maybe one more stat such as the heights of the trees. Let's break this down into one plot to add a dropdown for the neighbourhoods, then we'll facet the tree species again for a clearer look at the data using the heights given as well.

We can now see the data clearly but I would like to add some more interaction to each chart like zoom, color change based on selection but in order to do this, I'll have to create 4 dataframes for each species. Then I will add in a brush selection to highlight a certain part of the figure to show all the same height trees in a neighbourhood. The last selection tool I'll add is an ability to click on the color legend to isolate the odd, med, or even side of the street.

Ok, this is what I want to see! Here we can filter out the neighbourhood using the dropdown menu so that we could add in the heights of these trees as well. We can also use this chart to look at just the specific neighbourhood.

Observations using Figure 7

  1. Figure 8 has many locations where there is overlap of the height and number of trees when loaded, this gives us a hue variance as it suggests there are more than one tree which satisfies this condition. For example, there are multiple Cerasifera trees 4 m in height in various neighbourhoods. Once we use the dropdown menu to go to a specific hood, it clears it up
  2. Platanoides are clearly the tallest of the tree species with the tallest one living on the odd side of the street in Kerrisdale. In Vancouve the sun shines brightest on the odd side as it faces South, so this may be a result of that.
  3. Cerasifera trees are the shortest but not by much, the shortest tree is a Rubrum in Sunset on the ODD side.
  4. It looks like there is a pretty even split of Odd and Even street side planted trees

Original Questions to be answered

  1. What are the 4 most populated tree species? Surrulata, Cerasifera, Platanoides, and Rubrum are the most populated tree species in order.
  2. Which neighbourhood has the most and the least of each of these species?
    1. Surrulata - Mount Pleasant has the most with 44 and Downtown has 4.
    2. Cerasifera - Victoria-Fraserview has the most with 43 and Downtown has 0
    3. Platanoides - Shaughnessey has the most with 44 and Strathcona has the least with 4
    4. Rubrum - Downtown has 27 and Arbutus Ridge has 3.
        </li>
<li><font size="2" style='color:red;'>Does it matter what side of the street the tree lives on for height?</font> 8 neighbourhoods have the tallest tree on the even side whereas 9  neighbourhoods have the tallest tree on the odd, so this doesn't really tell us anything about street side mattering about tree height which makes sense when you look down a street, not often are the tree heights different from one side or the other.</li>
<li><font size="2" style='color:red;'>Which neighbourhood has the tallest what side of the street is it on?</font> 
    <ol>
        <li>Platanoides - Kerrisdale has the tallest at 8 metres and its on the odd side of the street</li>
        <li>Cerasifera - Many have the tallest at 4 m but Hastings is the only neighbourhood to have one at 4 on both sides of the street</li>
        <li>Surulata - Riley Park has the tallest at 5 metres and its on the even side of the street</li>
        <li> Rubrum - Killarney and Riley Park have the tallest at 6 metres and its on the odd side of the street</li>
    </ol>


   </li>
<li><font size="2" style='color:gray;'>Which neighbourhood has the most over amount of trees and which has the least?</font>  Renfrew-Collingwood has the most trees and Strathcona has the least.</li>

    </ol>